Rough prints on some angles
Hello,
I recently found that the screw holding the pulley to the flat part of the X-axis motor shaft had come loose. That led to some very wonky prints. I have since tightened the screw, and the 'front' surfaces are printing fine, but the 'back' of the prints comes out rough.
There is good tension on the belt (it 'pings').
Any suggestions as to what could be the cause of this?
Thanks,
Andrew
Re: Rough prints on some angles
Hi Andrew
Two things:
1. Looks like you are over-extruding - both front and back of the part shows signs of this.
2. The roughness at the back looks to be where each layer start/finishes with the over-extrusion showing up as roughness in that area.
Ensure that the filament is the diameter set in the slicer - measure it in two directions every 20cm over a 2M length and use the average of this in the slicer.
Reduce the flow rate - there should be a "flow tweak" setting in the slicer - reduce by 10% to start with to see if that helps.
Reduce the extrusion temperature by 10 degrees or so.
Reduce the "seam overlap" (or similar) setting in the slicer.
Set the extrusion width to the same as the nozzle width (0.4mm as standard).
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Rough prints on some angles
Thanks Peter. What are the signs of over-extrusion? The front side seems fine to me.
The start/finish of each layer isn't in these pictures, and there is a rough line along there. The section in the photos though is quite wide, and also occurs on flat surfaces which are 45º to the x and y axes.
What do you use to measure the filament diameter? I don't have any calipers, but i can probably buy one if necessary.
Re: Rough prints on some angles
Hi Andrew
The general roughness of the layers in that some are more pronounced than others tends to indicate over-extrusion.
Most slicers have a "seam hiding" option, where the the seam is positioned at corners or varied each layer on parts without corners.
I use cheap Chinese digital verniers to measure a whole load of things, including the filament diameter. Note that when measuring filament, it may be oval so you take 2 measures at each point, 90 degrees apart.
If you don't have the calipers, do a test print with each filament with a variety of flow rate tweaks to find the best (smoothest) setting for that filament.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Rough prints on some angles
For posterity, in case anyone else has this issue:
I've finally resolved my rough prints after a lot of changes. As with most problems, it was the simplest thing in the end.
I tried different flow rates as Peter suggested, set through the LCD/button interface on the printer. 80% was definitely too low, I couldn't see a difference between 90% and 100%, and in all cases i kept getting rough prints on the back of any model.
I changed from ABS to PLA and kept getting the same issue. (I kept using marvin as my test subject, and each time the back was rough with the same weird fishbone-ish pattern)
I printed 4 marvins on the same time at different orientations to verify that it was definitely certain angles that were the issue, and not a particular X-Y location on the print plate. I got rough edges at the 'back' of the x-plane in all prints (which was the front of one marvin and the side of two)
I figured it had to be something to do with movement - at least in the x axis and maybe in y-axis. Both motors seemed to turn cleanly, the idlers both seemed fine. The belt on the x-axis was a bit loose, so i tightened that, to no avail.
The X-axis carriage seemed to be sticking a bit, so I bought some replacement linear ball bearings (LM08UU).
I first replaced those on the Y axis, as it was easier - the carriage seemed to run a bit smoother, but i got exactly the same rough pattern, so that wasn't it. I then replaced those of the x-axis, and cleaned up the rods, which were indeed quite sticky and dirty (I suspect this was from spattered ABS juice when the spray bottle was still working). The printer has been quite busy for the last 5 months. Cleaning the rods seemed to make a big difference even with the old bearings, but i replaced the bearings anyway and got very smooth running before putting the x assembly back.
Very dissapointingly, even that didn't make a difference, i got the same rough pattern on the back of poor marvin.
I was running out of moving parts to fix, so at a whim decided to replace the nozzle.
That fixed it. No idea why, the old nozzle looks absolutely fine to me, but i now have one perfect purple marvin, and a dozen rough clones.
Printer has been working fine for the last day, and after a three week hiatus is back to printing.
Re: Rough prints on some angles
I'm having some bad print on this turtle as well. It started of slightly bad may be due to the size and the floating fin which needs support. But the support did not printed properly and destroyed the lower section.
The top part is fantastic. May be I should not print that small?
Re: Rough prints on some angles
The above prints seem poor. I suggest looking at Simplify3D's guide.
https://www.simplify3d.com/support/print-quality-troubleshooting/
Nigel
Life is keeping interested and excited by knowledge and new things.
Re: Rough prints on some anglest
I guess it was the slic3r which gave me some pretty hard time on printing complex object like this.
I've tried more than 8 times before I get the first turtle out and it's distorted in the mid print.
I've tried lowering the temperature , up the temperature, add support, slower speed. And I just could not get it out.
Lastly, I've paid for the Simplyfy3D and to my surprise it came out pretty good at first print. Just load the setting from Prusa website like I did for the Slic3r, and I seriously did not wait to start cause I was rushing to go out.
When I came back, it was perfect and no distorted or spoilt during mid print.
2 thumbs up for Simplyfy3D, no more wastage and first print a success.
I'm still not sure why that the Slic3r could not generate the support needed for the floating fin and the control of the flow might need more tweak. The simplify 3D just awesome , I've set what I've wanted, thicker walls, details and add support. I'll try more for this 2 weeks to commit on simplyfy3D 🙂
Re: Rough prints on some angles
Hi Zach
When printing with support, you will never get a great finish on the interface. And support is quite a minefield with all the many and various settings available.
If you want a good finish all over, they you will have to consider ABS + acetone smoothing at some point. Unfortunately, I believe PLA can only be smoother with chloroform which I would rather not use...
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Rough prints on some angles
I'm not looking at smooth printout but rather than a good print session. I mean Simplyfy3D gave me almost 100% print success but with Slicer i need to observe the first few layer and always screw up in the mid print. which i do not know why. Might need to put a camera to find out.
I'm wondering if the setting from Prusa has been tested but the default setting which i have loaded to both of the softwares , Slicer and Simplify 3D are totally not the same. With Slicer the nozzle temperature is always at 210 celsius but in Simplyfy3D, its set at 215. But the print i can say is 100% no failure.
I can just export code to my SD , click start print and come back looking at it smiling. With Slic3r , i have to design my object nicely and hope that it'll print out nicely 😛 ... I'm a bit of frustrated when it screw up at the mid print which wasted lots of PLA and time.